Prior art valves for possible use with airbags includes those described in U.S. Pat. Nos. 4,719,943 (Perach), and 5,855,228 (Perach), both of which are incorporated by reference herein.
Also, U.S. Pat. No. 5,653,464 (Breed et al.) discloses a variable vent hole for an airbag (FIGS. 7 and 7A). The variable vent is formed in a seam of the airbag and includes a hinged elastic member biased so that it tends to maintain the vent in a closed position. As pressure rises in the airbag, the vent is forced open. The vent contains an opening formed between a film layer of the airbag and a reinforcement member. The film layer is also sealed to the reinforcing member
The flow of gas out of an airbag may be controlled during inflation and deflation of the airbag based on the morphology of the occupant for whom deployment of the airbag will be effective as disclosed in U.S. Pat. No. 5,822,707 (Breed et al.), incorporated by reference herein. This patent, as well as others assigned to the current assignee, further describes that the gas outflow may also be controlled based on other properties of the occupant to be protected by the deploying airbag including but not limited to the occupant's position, identification and type.